Liquid chromatography-tandem mass spectrometry method for simultaneous quantification of neurotransmitters in rat brain tissue exposed to 4'-fluoro-α-PHP

The combination of different advanced analytical techniques makes it possible to determine the concentrations of neurotransmitters in various biological matrices, providing a complex and comprehensive study of the effects of psychoactive substances. The present study aimed to develop and validate a fast and simple analytical method for the determination of acetylcholine, serotonin, γ-aminobutyric acid, glutamate, dopamine and metabolites in rats brain tissue by liquid chromatography coupled to tandem mass spectrometry. The brain was homogenized and aliquots of the sample, dopamine-d₄ , and acetone were added to a tube and then vortexed and centrifuged. The supernatant was collected and dried. The residue was reconstituted and injected. The LLOQ ranged from 0.001 to 1 μg/g; the intra-run precision ranged from 0.47 to 11.52%; the inter-run precision ranged from 0.68 to 17.54%; and the bias ranged from 89.10 to 109.60%. As proof of concept, the method was applied to animals exposed to the synthetic cathinone 4'-fuoro-α-pyrrolidinohexanophenone (300 mg/kg). In addition, the workflow proved to be simple, rapid and useful to estimate the concentration of neurotransmitters. This analytical tool can be used to support the investigation of the changes in the neurochemical profile for the characterization of the mechanism of action of psychoactive substances, as well as both neurological and psychiatric diseases.